This Center Grant proposal seeks partial support for the core units of the Population Studies Center. The core units include 1) administrative services, 2) data and program development, 3) the library, 4) editorial services. The program of the Population Studies Center has three major emphasis: basic behavioral-social science research in population, particularly within a social, social-psychological, economic, or ecological framework; graduate training in population and human ecology; demographic assistance to governments and international agencies with particular emphasis in developing countries. Much of the research at the Center is related to two broad foci: fertility and family planning and population distribution and differentiation. Another broad area of Center research involves historical demographic analysis. Along with substantive research, there has been a strong methodological focus in the work of the Center.